Decreasing requirement for lithium carbonate therapy in bipolar affective disorders (hypomanic type) following the onset of chronic renal insufficiency.

The importance of regular monitoring of both serum lithium and creatinine levels, together with thyroid function assessment, in a patient taking lithium carbonate therapy for bipolar affective disorder (hypomanic type) is emphasised. In this case it was the gradual rise of serum creatinine that alerted the physician to the onset of insidiously progressive renal impairment. In the absence of any evidence for another aetiology, it was concluded that a possible cause for the renal problem was the lithium therapy itself. By reducing the dosage it was found that serum lithium levels were maintained within the reference range, thus avoiding the potential psychiatric consequences of high concentrations--which could well have occurred had the former dosage been continued during the period of deteriorating renal function. The situation is currently being carefully monitored in case another cause for renal disease, other than that of a side-effect of therapy, emerges at a later date.